Hydraulic clutch



Dec. 22, 1942. w. A. ROTH 2,306,353

HYDRAULI C CLUTCH Filed Oct. 18, 1940 \MILLI M F1. RUTH Patented Dec. 22, 1942 UNITED STATES PATENT OFFECE HYDRAULIC CLUTCH William A. Roth, St. Paul, Minn. Application October 18, 1940, Serial No. 361,703

H Claims. (01. 192-61) My invention relates to a new and improved hydraulic clutch wherein it is desired to provide a more practical and efilcient form of hydraulic clutch.

It is a primary object of my invention to provide a rotary type fluid pump in combination with other elements including a governing device which shall maintain a pressure opposed to a fluid pressure developed by the pump. This governing device operates to develop a pressure somewhat greater than the minimum pressure at any given engine speed, but somewhat less than themaximum pressure at this speed. These minimum and maximum pressures are proportional to the minimum and maximum torque capable of being developed by the engine or other suitable source of motor power at all speeds from idling speed to the speed where the greatest maximum torque may be developed. Y

a It will be understood that at any engine speed,

the maximum torque which the source of power is capable of developing is instantly made available when necessary. For example, an automobile travelling at a predetermined rate'of speed and desiring to pass another vehicle may suddenly require greater than ordinary acceleration. The maximum torque the engine is capable oi' developing may thus be made available. My governor device is so arranged that where minimum torque is required for a predetermined speed, the valve will remain closed, but if unusual torque is required, such torque is rendered instantly available.

It is a feature oi my invention that my clutch is of a type which permits quick and ready reversibility. This construction makes by'device particularly attractive for use in certain flelds. When in use upon a boat or ship, it enables the ship to be quickly and readily maneuvered, thus enabling a warship, for example, to turn and reverse more a quickly than would otherwise be possible. The

reversibility of my clutch when used with a suitable reversing gear is such as to prevent the creaticn oi stress which may readily damage the power plants or the boat, vehicle, or plane in which. it is located when full power is thrown in reverse. The reversible feature of my clutch is useful on other powered objects such as airplanes, tor the speed of a plane might be quickly checked Up to the present time planes have depended'ior anti-aircraft flre and attacks from other planes. With my quickly reversible clutch, a change of speed may form as important a maneuver to avoid destruction as a change of direction.

. My clutch is particularly adapted for use on locomotives or the like in sections where the use of electrical current is common. By using an electrical motor for operating my fluid clutch, which in turn may drive the locomotive through a power device such as that disclosed in my copending application, Serial No. 307,104, an alternating current power supply may be used. Thus by this means the direct current electrification systems which are extremely costly to construct and maintain may be eliminated and alternating current supply sources used in place thereof.

It is a further feature of my invention that my device may be used in combination with Diesel engines to drive Diesel locomotives and the like. With my device, the engine may be driven at a speed where it will develop suflicient torque to start a train and when used in combination with some mechanical gear shift arrangement or device such as I have illustrated in my aforementioned copending application, a heavy train may be started into motion and driven effectively at any desired speed.

This application is a continuation in part-of my copending application, Serial No. 307,104, filed December 1, 1939, for Automatic hydraulic transmission."

These and other objects and novel features of my invention will be more clearly and fully set forth in the following specification and claims.

In the drawing forminga part of my specification:

Figure 1 is a cross-sectional view through my clutch device. Figure 2 is a cross-sectional view, the position of the section being indicated by the line 2-2 of Figure 1.

Figure 3 is an enlarged cross-sectional view of a passage valve opening illustrated in Figure 1.

Figure 4 is an enlarged cross-sectional view of a second valve passage also shown in Figure l.

The present invention embodies a rotary pump which may boot the reversible type and which is used in combustion with a novel type of governor. This governor which will be later described in detail has the function of supporting the valve associated therewith operable in closed position when minimum torque is required and in open position whenmaximum torque is required at any engine speed.

the most part upon change of direction to avoid In desi ning the device it i necessary to coinof the motor does not immediately increase, but

the torque load upon the same does. Thus at each speed of rotation, a minimum and maximum torque requirement may be plotted.

If the pressure developed by the pump actuated by the motor is plotted against the speed of the motor, two spaced curves will be attained, one of which represents the minimum pressure corresponding to the minimum torque, while the other curve represents the maximum pressure corresponding to the maximum torque requirement. It is desired that the governor be so constructed 2,soe,ses

positioned in the inlet to th pump so that the check valve 2| will permit'liquid to flow into the casing to provide a source of fluid supply for the pump. The valve opening 25 is provided with a valve 33 which is equipped with a valve stern 34. A'sleeve 35 encircles the valve stem 34 and a spring 36 is positioned between the end 3'! of the sleeve 3i and the end of. the valve stem 34. The cap end 31 of the sleeve Ii is drilled to provide an inlet or outlet for liquid so as to equalize pressure on both sides-of the sleeve II. This opening 39 may be of such a size as to dampen the movements of the sleeve 25 with respect to the stem 24.

that it will at any speed maintain a pressure valve leading to the pump closed when a minimum torque is required at any speed, and to permit the valve to open when a maximumv torque at any speed is required. This I have accomplished and the governor controlled valve will open between the maximum and minimum pressures developed.

the partition ll into engagement with the closure. -wall i2 to form aseal therebetween. Thus apair of shells or sleeves I I and ii which are concentric in their relationship are provided. A boss I6 is provided on the closure l2, and a drive shaft l1 extends through a packing joint it between the shaft l1 and the boss I. a reversible rotary pump is keyed at 2| to the shaft II. A liner ii is disposed between the sleeve ll andtheroiorfl andisheldsecurelyin place by the sleeve II.

Within the rotor 2| I provide a cooperable pump gear 22 mounted on a stub shaft 23 preferably forming a part of the partition wall i I. The gear wheel 22 is eccentrlcally mounted with respect to the outer rotor 20, and between these two gear elements, I provide a moon-shaped filling element 24, which engages the teeth of the gear wheel 22 and the rotor 20 to fill the space therebetween.

The parts 20, 22, 23 and 24 comprise a pump B. The pump B which has been described has two passages 25 and 26 leading therefrom through the shell l5; Additional passages 21 and 29 through the shell I! are equipped with check valves 30 and II which permit liquid to flow freely into thepump but prevent the discharge'of liquid therethrough. These check valves are shown with pivot closure valve elements 12, but it should be understood that any desired type of checkvalve could be used which is of the propersize to permit a free flow of liquid into the pump when it is necessary.

- Rotation of the shaft l'l acts to rotate the pump rotor 20 to drive liquid either toward the valve opening 2' or the valve opening 28. Let us say that in a forward direction the reversible pump rotor causes Pressure at the valve in the valve opening 25. The valve opening 26 will then be The outer rotor 20 of' Anend closure I2 A pair of links 40 are pivotally secured at 4| to thesleeve cap 31. These links 40. ar pivotally connected at 42 to'levers 43 which are pivoted at 44 to iixed supports 45. Governor weights 46 on the arms 43 act to-pivot the levers 42 upon centrifugal movement of the casing and various elements, causing an inward pressure on the sleeve 35 to compress the spring 36 and to-tend to iorce the valve 33 against its seat.

A valve 41 is positioned in the seat of opening 28 having a valve stem 40. This valve stem 48 is telescopically supported in a sleeve 50 having a cap end ii pivotally secured at 52 to a pair of links 53. A spring I4 is positioned between the end 5| of the sleeve 50 and the valve stem 48 tending 1 to urge the valve inwardly against its seat. An

opening 55 is provided in the'cap end ll of the proper dimensions to dampen the movement of the sleeve 50 with respect to the stem 49.

The links 53 are pivotally connected at 58 to levers U which are pivotally supported at 58 to supports 60 secured to the sleeve I5. Governor weights 6| are provided on the ends of the levers 51 which are thrown outwardly by centrifugal force tending to compress the spring 54 and to urge the valve 41 against its seat 25. If the clutch is not to be of a reversible type, the second valve 4'! and its associated mechanism is unnecessary.

Supports 62 are provided for the weights 4S to limit the inward movement thereof and to initial tension on the spring 54.

space betwen the sleeves i5 and iii to the reservoir 66 located between the partition wall It and the end closure I3 and extending to the full diameter of the clutch. .A similar opening I1 is provided in the partition wall ll leading to the chamber enclosing the oppositely disposed governor. The chamber shown between the sleeves I0 and It at the top of Figure 1 is separated from the chamber shown at the bottom of Figure 1 between these rings by means ofwebs 81, so that in order to get from one chamber to the other, it is necessary to pass through the openings 65 and 61, or through additional openings 6! and 10. A check valve II is provided over the opening 69 and a'similar check valve 12 is provided for the opening 10. Thus on the inlet side of the pump, the check valve II or- 12' may open to permit a free flow of liquid from the reservoir 86 into the chamber associated with the pump inlet and the check valve 30 or 3| may also open to provide an open passage into the pump chamber. A brake band 13 which may band 13.

' bottom of Figure 1 through passages 61 and from the reservoir 68. At the same time liquid under pressure is forced from the outlet end of the pump past the valve 33. It will be seen that the check valve 33 is closed at theoutlet pump must pass the valve 33. Some initial pressure against the valve 33 is provided by the spring 33, but this pressure is not too great to permit the valve 33 to open somewhat and to provide a slow circulation of liquid past the valve 33 out through the opening 65 into the reservoir 85 from which it is directed to the intake of the pump in the manner which has been previously described.

The back pressure of the spring 38 against the valve 33 is not sufilcient to providerotation of the casing when the motor driving the shaft H is travelling at idling speed. In other words, the natural resistance to movement of the vehicle containing the hydraulic clutch A is suillcient to rotor and the casing as the speed of the casing increases For example, when the pump rotor is travelling at a speed of for example 1000 R. P. M., the outward pressure created by the pump may be thirty-eight pounds, while the maximum outward pressure which can be developed by the pump in case of maximum torque or resistance may be forty-two pounds. The inward presend of the pump so all fluid escaping from the sure on the valve 33 is then designed to be approximately forty pounds, so that the valve will remain closed when a maximum torque is required and as the casing slows down will open when a minimum torque is required. I

It will be noted that my governor is so devised that an increase in speed of the driven casing will act not only to increase the centrifugal force by the increase of speed, but also the governor weights 43 or Cl will be swung outwardly so that they travel in a longer orbit, thus increasing the pressure tending to hold. the valve closed.

When it is desired to reverse the rotation of the casing, the pump is reversed so that the passage I! normally closed by the valve 41 forms the outlet, while the passage and opening 21 form the inlet to the pump. The action is identical to that which has been described, the governor shown at the lower end of the figure takhold the car stationary, while the force of the pump opens the valve 33 and causes circulation of liquid. Any tendency to rotate the driven member may be overcome by tightening brake As the speed of rotation of the shaft i1 is increased, a greater pressure is urged against the valve, opening this valve to a greater extent and forcing more liquid therethrough. The size of the outlet 85 is so proportioned that a greater flow of liquid will cause sufllcient back pressure to start rotation of the casing with the pump. In other words, the liquid expelled by the pump. is in such a quantity that it cannot pass through the aperture 65 as quickly as it is expelled from the pump, thereby causing movement of the casing and the pump, the casing travelling at a speed which the passage of oil through the aperture 65 will be equal to the flow of oil from the pump into the chamber con-.

nected to the outlet and positioned between the concentric sleeves I0 and [5. In other words. there will be some slippage between the speed of rotation of the pump and the speed of rotation of the casing, the amount of this slippage being adjusted by the position of the valve 33 and the size of the outlet 65.

As the casing startsto rotate, the governor weights 46 and 6| pivot outwardly increasing the 4 tension of the spring 36 against the valve 34, and Thus as the to prevent relative slipping between the pump ing the place of the governor shown at the top of the figure and regulating the flow of liquid from the pump casing.

I have found that if the valve and the various openings are properly proportioned, certain of the, openings may be omitted from the construction. It is possible that the valve 33 or 41 may be properly proportioned to take over the function of the orifice 35 and this orifice 65 and the check valve 33 and its corresponding function may be eliminated.

It will be noted that when the shaft I! is travelling at a low rate of speed, the liquid forced the shaft will cause a back pressure due to the restriction in size of the orifices 65 or 61 and rotation of the casing will occur. In case the speed is changed from forward to reverse, the brake band 13 may be used to stop the casing so that it may be quickly rotated in the opposite direction.

Obviously 'the specific position of the governor and the various parts is not important and the governor may be positioned either in the manner shown or in a direction at right angles thereto. Furthermore, the position of the various ports should not be important so long as the function of theseports is the same. The governor must be so proportioned that the weights on the weight arms will be overcome by the weight of the various other parts forming the governor so that the governor will act in the manner described. By changing the proportions of the levers 43 and changing the position of their mounting and by changing the angle at which these levers remain, it is ,possible to obtain virtually any desired action on the part of the governor so that the pressure tending to close the valve 33 or 41 will be intermediate the outward pressure against this valve when minimum and maximum torque is required. After the point of greatest maximum torque developed by the engine has been reached, the pressure tending to close the valve 33 or 41 will no longer remain intermediate the minimum and maximum torque pressures and the valve 33 or 41 will remain closed at speeds above the eration oi my hydraulic governor: and while I 4 have endeavored to set iorth the best embodiment thereof, I desire to have it understood that this is only illustrative of a means or carrying out my invention and that obvious changes may be made within the scope oi the iollowing claims without departing from the spirit of my inven-' tion.

I claim:

1. A hydraulic clutch comprising a pair 0! concentric sleeves, closed ends thereon. a pumpin the inner or said sleeves, a drive shaft for said pump extending through one oi said closed ends, an inlet and an outlet to said pump through said inner sleeve, a pair of chambers between said sleeves, one of which is connected to said inlet and the other of which is connected to said outlet, a common reservoir connecting said chambers, a valve in said outlet, means in said casing operable by centrifugal force upon an increase in the speed of rotation oi said casing to urge said valve toward closed position, and orifice means between said chambers and said reservoir of a size to restrict the flow of liquid between said chambers.

2. A hydraulic clutch comprising a pair of concentric sleeves, closed ends on said, sleeves, a reversible pump within the inner of said sleeves,-

- said inner sleeve having a pair of passages therethrough, a pair of chamber: between said sleeves,

a common reservoir connecting said chambers,

one oi which is connected to each oi said passages, valves in said passages, means operable by an increase in rotary speed of said casing to urge said valves toward closed position, said inner sleeve having a second passage from each said chamber to said pump, check valves in each said second passage to permit liquid to flow therethrough in one direction only, and. a restricted passage between said chambers andsaid reservoir.

between said sleeves, one c! which is connected to said inlet and the the other of which is con nected to said outlet, a valve in said outlet,

means operable by an increase in the speed of rotation of said casing to urge said valve toward closed position, said partition wall having a restricted orifice therein between said chamber connected to said outlet and the space between said partition wall and said other closed end, and said partition wall having an opening therethrough between said chamber connected to said inlet and said space between said partition wall and said other closed end.

4. A hydraulic clutch comprising a hollow cylindrical casing having closed ends, a partition wall parallel to, and spaced between, said ends, an inner sleeve concentric with said casing extending between said partition wall and one oi said closed ends, a reversible pump within said sleeve, a pump drive shaft extending through.

said one closed end, said sleeve including a pair of angularly spaced passages to said pump, either of which may act as the outlet while the other passage is closed, a pair of chambers between said casing and said sleeve, one of which is in communication with each passage, a reservoir in the space between said partition wall and the other of said closed ends, a valve in each said passage, means operable by an increase in the speed oi rotation of said casing to actuate said valves to urge the same toward closed position, said partition wall having restricted orifices therethrough, one of said orifices communicating with each 01' said chambers, said partition wall having a pair of additional openings there'- through, check valves in said partition wallpast which liquid may flow from said reservoir into either 01' said chambers, said sleeve having additional passages from each said chamber to said pump, and checkvalves in said additional passages past which liquid may flow toward said D mP- I 5. A hydraulic clutch comprising a hollow cy lindrical casing having closed ends, a partition wall between, and parallel to, said closed ends, an inner sleeve within said casing between said partition wall and one of said closed ends, a pump within said sleeve, 9. drive shaft through said one end to said pump, an inlet and an outlet to said pump through said sleeve, a pair of chambers between said sleeves, one of which is connected to said inlet and the other of which is' connected to'said outlet, a valve in said outlet, means operable by an-increase in the speed of rotation of said casing to urge'sald valve toward closed position, said partition wall having a restricted orifice therein between said chamber connected to said outlet and the space between WILLIAM a ROTH.

. stationary. 

